Bob and ID,
Thanks for the quick feedback.
I've never had a sailboat, and was wondering how often would the electric motors be used. My impression is that they would only be used leaving and arriving at port.
I can see how the propellers would cause drag while charging the batteries, but wouldn't a wind generator help too?
I actually spoke to a Lagoon dealer on the phone, and he told me how Solomon virtually gave up on the hybrids because of problems with the chargers. Of course I didn't get details, but it seems there would be so much potential using free wind power and/or solar panels while cruising and on the hook.
Even in a motoryacht (my experience) you can only run major appliances with the generator running. So I'm not getting the shortfall, unless the batteries aren't capable of a minimum necessary to pull into port. Maybe people were trying to cruise the intracoastal all day just on batteries?
Your thoughts please.
Thanks,
George

The only application I see that is feasible is to put in a dieselgenerator which can be mounted anywhere on the boat (bow) with propulsion being an electric motor at the stern.
You would have to run the diesel generator whenever you wanted to move anywhere.
Batteries just do not hold enough usable storage energy and solar panels are a joke. In my experience (i have 5x 200watt solar panels) they put out only about 1/2 what the manufacturer says and, and only for a few hours a day

George, your questions are good ones, but the answers are complex and would take a lot of time and space. Believe me, I almost bought one of the 420's when they were first being proposed. After seeing them in person, I made other decisions. There has been lots written about the various topics, though and I suggest you look at:

Yeah they'll pull you into port but that's about it. Frequently you will be stuck with no or low wind or wind on the nose so you want the ability to motor for a couple of days. Hybrids just can't do this. Not even close. The opposite issue is high winds where you want to motor. I recall a comment that they could only do 40 to 60 miles on a charge and the batteries take a while to charge. And the boats are extremely slow. A wind generator will help but still nowhere near the power to make a dent. We are talking about massive amounts of electricalconsumption. Way more than refers and AC combined. Diesels are the only way to go. BOB
PS. If you read the Bumfuzzle blog you will see that they were becalmed quite a bit and motored halfway (it seems) across major oceans. You want that option.

Bob,
Thanks for the info.
Yeah, I watched the Bumfuzzle and the Honeymoon videos and noticed how they had so many containers with fuel.
But I also heard in a video how in highwinds a Lagoon owner would use one of the motors to maintain the course, kind of compensating. Does that make sense?
I didn't quite understand the technique.
Care to lead me to a link on that too please?
Thanks,
George

George, your questions are good ones, but the answers are complex and would take a lot of time and space. Believe me, I almost bought one of the 420's when they were first being proposed. After seeing them in person, I made other decisions. There has been lots written about the various topics, though and I suggest you look at:

Why wouldn't running a generator any time you run the electric drives work just fine?
Isn't that the basic principle involved with modern train locomotives? Well, maybe not super modern, but I'll bet that magnetic propulsion is a little ways off from the boating world...
Anyway, If you have a proper sized generator, anytime you need to use the electric propulsion, you run the generator. You make water. You do laundry (if so equipped). You charge up the pleasure vibe,etc......
And your house batteries are kept charged to optimum capacity.
Once you are intimately aware of your battery capacity, you should know if it's OK to use the electric propulsion for a short burst or so.
What's the harm in running the one generator that could be multitasking so easily, where you would usually be running one or two diesel engines, or gasoline outboards?
Maybe there have been some growing pains with all this new fandangled electric propulsion stuff, maybe it's more just the owners not quite understanding the intricacies of battery management and a life at sea relying on them?
For the past 12 years I have lived off the grid. Relying on my large 12volt battery, 1200 watts of solar, a small wind turbine, my generator, and my brain. I run my super efficient, 12 volt floor heat pumps, 12 volt refrigerator, and 12 volt lights. I also have a 2500 watt inverter/charger that is used for a few other lights, water pump, etc. When I want to feel special and watch TV... I start the generator! Well, at least in the winter around here!
Point being, I would think that these electric Lagoons (and any other electric powered boat) would want the generator running anytime they are using the electric propulsion for more than a couple of minutes.
If you run the electric motors for ~10 minutes, then get sailing and realize your batteries are significantly below their optimum state of charge, it will take probably 30 minutes of genny time to try and stuff the same amount of electrons back into batteries that you just pulled out in 10. However, if you just run the damn genny whenever you motor, you are not taxing the batteries at all! In fact you would be charging!
In the end, your batteries, and you, would be happy campers!

Sol, in physics there is no such thing as a free lunch. So, to create say 100 HP of propulsion you will need more than a 100 Hp genset due to losses in converting the mechanical energy to electrical energy. These losses in energy are through a conversion to heat. I don't know why trains use it but they definately don't try to move on battery power. However the hybrid Lagoons were supposed to be able to cruise on battery power for a while and sadly the technology isn't there yet. As ID said there were numerous problems with the systems and the weight of the batteries. They were unreliable, hot, expensive, heavy and slow. Solar and wind generators would be a very small fraction of what is really needed to charge the batteries and/or move the boat. What's the point of going green if you are still filling up with diesel for less power than if you just bought the engines and genny in the first place? That would be going un-green. It's a great idea in theory but I don't want to pay for the R&D. BTW the other guy did PM me and you can as well. This thread is drifting. BOB

Sol, in physics there is no such thing as a free lunch. So, to create say 100 HP of propulsion you will need more than a 100 Hp genset due to losses in converting the mechanical energy to electrical energy.

Sorry for the thread drift. Moderators can take care of that. PM'ing just hides valuable info.

Likewise, a 100 hp engine loses much of its hp through mechanical inefficiencies in its gearbox and sail drive. I stand by my previous post. One engine taking care of electrical needs and propulsion needs and the ability to put it anywhere on the boat is a pretty good idea!
If the mods, or you, Sand Crab, would like to start a different thread for this stuff, that'd be great.
BC

SOL, You would have sail drives or shaft drives in either type of application so that would be a wash. You might be able to delete the tranny. Did the 420s have them? Could the motors spin backwards and operate at low RPMs? I also wonder what the energy loss in the conversion of mechanical to electrical would be. The point I was poorly trying to make earlier was that the largest sailboat builder on the planet couldn't make it work so I'm not going to try. It's also the availability of parts and quality service that scares the crap out of me. You can get that Yanmar serviced at virtually every marina on the planet. Try doing that with Almagomated Industries Hyperdrive Motors (joke). However, I agree with your concept of 2 different size engines. In this boat and others I've seen he did away with the gen and has a direct drive for AC and refer compressors and the other side has some high output alternators. Catamaran 1999 Berkstresser 60 Catamaran For Sale
Is this the best of both worlds? BOB

As fascinating as this discussion on hybrid drives is why don&rsquo;t you start a thread in the right location?
It will make it easier for people to find this info in the future.

Dear Dragon Lady,
I actually found the subject in the TOC, but got nowhere.
So I posted the question on my own.
Not getting the hang of this yet, like my PM reply to someone which ended up with the moderator.
Velejador